Process of preparing a finishing composition containing aziridine radicals used for reducing the shrinkage and felting of wood

ABSTRACT

British Pat. No. 1,470,243 relates to aziridine compounds suitable for finishing wool, but the method of formulation, described there, of these compounds for practical purposes proved unsatisfactory. This problem is solved by the present invention.

The present invention relates to an improved process for the formulationof compounds of the general formula I, ie. for their conversion into aform suitable for use.

British Pat. No. 1,470,243 relates to compounds containing aziridineradicals, of the general formula I ##STR1## where R¹ to R⁷ are hydrogenor low molecular weight alkyl, Q is the radical of an n-hydric alcoholor phenol, n is 2 or 3 and X is a polyether chain of butoxy and/orpropoxy units, with or without ethoxy units, which chain has an atomicratio C:O of not less than 2.67:1 and a molecular weight of from 150 to1,500 if n=2 and from 150 to 3,000 if n=3, and to a process for reducingthe shrinkage and felting of wool by means of such compounds.

The type of formulation described there is relatively expensive; itrequires intensive stirring and relatively large amounts of emulsifier,which impair the hand of the finished textile, make it undesirablyhydrophilic and increase the ease of soiling. Furthermore, in the caseof the formulation according to the above British Patent, application bythe exhaustion process presents problems.

It is an object of the present invention to provide an improved processfor the formulation of the finishing agents according to the saidBritish Patent, which process in particular overcomes the saiddisadvantages.

We have found that this object is achieved by providing the processdefined in the claims.

The surfactants used are adducts of alcohols of 8 to 18 carbon atomswith from 5 to 80, preferably from 10 to 30, moles of ethylene oxideand/or adducts of alkylphenols, where alkyl is of 8 to 12 carbon atoms,with from 5 to 80, preferably from 7 to 20, moles of ethylene oxide, thehydrophilic radical, ie. the number of ethylene oxide molecules whichhave undergone adduct formation, being in each case in a suitablybalanced ratio to the size of the hydrophobic radical. If, at a lowdegree of oxyethylation, the emulsifying action is insufficient, it canbe improved by adding other emulsifiers, for example an adduct ofp-benzyl-o-phenylphenol with about 10 moles of ethylene oxide.Particularly preferred surfactants are the adducts of from 10 to 20moles of ethylene oxide with aliphatic alcohols of 10 to 14 carbon atomsand of from 7 to 20, especially of from 9 to 15, moles of ethylene oxidewith nonylphenol. The lower limit of the amount of ethylene oxide to beused advantageously in forming the adduct is imposed by the emulsifyingaction of the surfactants, ie. the stability of the emulsions. The upperlimit follows from the decreasing solubility in the active compound, oractive compound solution. The same criteria also determine the limits ofthe amounts of surfactant advantageously to be employed. These limitsare from 2 to 20, preferably from 6 to 14, percent by weight, based onactive compound (formula I).

"Dilute aqueous acid" means an aqueous solution of any organic orinorganic acid, having a pH of from about 1 to 5. Depending on thecontent of basic impurities (for example calcium oxide), in the mainoriginating from the process of manufacture, in the active compound, anddepending on the concentration of the aqueous acid, a greater or lesseramount of acid, as a rule from about an equal amount to twice the amountby weight of 1 N acid, based on active compound, is required to obtain aclear solution. In view of the danger of aziridine ring cleavage it isadvisable not to employ an unnecessarily large amount of acid and toneutralize the acidic solution immediately after it has been producedand the nonionic surfactant has been added. The nature of the acid isimmaterial. Examples are water-soluble aliphatic monocarboxylic anddicarboxylic acids of 1 to 6 carbon atoms, preferably formic acid andacetic acid, and the industrially most important inorganic acids, ie.hydrochloric acid, sulfuric acid and phosphoric acid.

The active compound can be dissolved directly in the aqueous acid.However, it is simpler and therefore more advantageous first to dilutethe active compound with from 10 to 1,000, preferably from 30 to 200,especially from 50 to 100, percent by weight of a water-miscible solventwhich boils below 160° C., preferably below 100° C. Examples aremethanol, ethanol, propanol, i-propanol, i-butanol, acetone, methylethyl ketone and N-methylpyrrolidone. Tetrahydrofuran, however, has beenfound to be less suitable. As a result of the dilution with the solvent,the active compound, which in the pure form is generally pasty, can behandled more easily and dissolves more rapidly in the aqueous acid.

The sequence in which the surfactant and active compound or activecompound solution are added to the aqueous acid is immaterial. It hasproved expedient to dissolve the surfactant in the solution of activecompound before adding this solution to the acid. As a rule, this methodfurthermore does not require the use of particularly intensive stirring.As soon as a clear acidic aqueous solution has been obtained, the pH isbrought to from 5 to 10, preferably from 7 to 9, by adding aqueousammonia solution. If the wool to be finished has been treated beforehandwith an oxidizing agent and/or chlorinating agent, a pH of from 6 to 8(instead of from 7 to 9) is preferred for the finishing liquor. Theammonia solution should be dilute so that no precipitate is formed. Ifit is desired to use a fairly concentrated ammonia solution, it isnecessary to stir intensively whilst adding the ammonia. In principle,any other alkalis can also be used, but ammonia has the particularadvantage that the ammonium salts formed, in contrast to the salts ofstrong bases, catalyze the subsequent fixing of the active compound towool. It is true that amine salts would also exhibit this effect, butamines would not offer any advantage over ammonia and would be moreexpensive.

The finishing agents are now no longer in the form of a solution but ofan emulsion. The emulsions are translucent. The higher the pH, the moremilky the emulsion. The shelf life increases with increasing pH and atpH 8-9 is of the order of magnitude of several days to several weeks.

Finally, the solution is diluted to the desired concentration, whichdepends on the amount which it is intended to apply, and on the wetpick-up. Of course, other materials, for example other finishing agents,catalysts, for example sodium bisulfite or ammonium bisulfite, and otherassistants can be added to the liquor.

It is a surprising aspect of the formulation process according to theinvention that the aziridine radicals, which are generally reputed to beacid-sensitive, withstand this method of treatment without loss ofactivity, and that surfactants have been found which preventflocculation of the finishing agent when the pH of the treatment bath israised, but do not detract from the non-felting effect.

The advantages of this novel process over that described in the aboveBritish Patent in which the compounds containing aziridine groups anddissolved in a water-immiscible solvent are emulsified directly by meansof an emulsifier system are, inter alia, that the preparation of thetreatment liquors is substantially simplified, since the solution of theactive compound in the organic solvent can be directly dissolved inacidified water, without using a stirrer, that the amount of emulsifierused is substantially reduced, so that the finished textile is lesshydrophilic and has a better hand, that the range of possibleapplications is extended, since finishing can be carried out by theexhaustion method, which is not possible with the relatively coarseemulsions obtained according to the process of the above British patent,that the wet soiling and dry soiling characteristics of the treated woolare improved since the finish contains less of surfactants which have asoftening effect, and that the non-felting effect is improved as aresult of the finishing agent being distributed more finely over thetextile.

In the Examples which follow, parts and percentages are by weight; inthe case of data relating to wet pick-up and amounts applied to thefibers, the percentages are based on the weight of the dry fibermaterial. The relaxation shrinkage and felting shrinkage are shown inthe Tables as the percentage shrinkage in area of the test specimen.

EXAMPLE 1

47 g (a) or 71 g (b) of a mixture of 50 parts ofpolytetrahydrofuran-2,000 bis-β-aziridinopropionic acid ester (activecompound), 5 parts of a polyadduct of 14 moles of ethylene oxide (EO)with 1 mole of nonylphenol and 45 parts of isopropanol are stirred into47 g or 71 g of 10 percent strength acetic acid and the mixture is madeup to about 800 ml with water. After it has been neutralized with diluteammonia and 70 g/l of a 10 percent strength ammonium bisulfite solutionhave been added, the mixture is made up to 1 liter and the pH of thefinishing bath is brought to 7-8.

Two lengths of an undyed double-knit jersey of pure new wool weighing300 g/m² are impregnated with these liquors, squeezed off to 85% wetpick-up on a padder, stretched to the initial width on a pin tenter anddried for 8 minutes at 130° C. in a through-circulation dryer.

The finished samples are washed, together with a non-finishedcomparative sample, for 3 hours at 40° C. in a Cubex machine. The washtest corresponds to Specification IWS/TM 185 of the International WoolSecretariat. The results are shown in Table 1.

                  TABLE 1                                                         ______________________________________                                                 Amount                                                                        of active                                                                     compound   Relaxation  Felting                                       Example    g/l     in %     shrinkage shrinkage                               ______________________________________                                        1a         23.5    2        6.4       7.8                                     lb         35.5    3        4.6       3.8                                     Comparative                                                                   sample     0       0        15        38                                      ______________________________________                                    

EXAMPLE 2

Sizable pieces of a carded wool fabric and of a worsted fabric aretreated with liquors which contain 67 or 10% of the mixture of activecompound, surfactant and i-propanol described in Example 1. The batchesare formulated as described in Example 1 except that the amount ofacetic acid is 6.7 and 10%, respectively, of the amount of liquor. Thefabrics are impregnated, and squeezed off to a wet pick-up of 60%, on apadder. They are then dried on a tenter with 12% overfeed, at 130° C.and a speed of 5 m per minute. The non-felting effect is determined bythe IWS test method, as in Example 1. The results on the finishedsamples and on the non-finished comparative samples are shown in Table2.

                  TABLE 2                                                         ______________________________________                                        Amount                                                                        of active                                                                     compound            Relaxation  Felting                                       Sample     g/l     in %     shrinkage shrinkage                               ______________________________________                                        Worsted                                                                       (comparative                                                                  experiment)                                                                              0       0        5.2       49                                      Worsted    50      3        3.6       5.3                                     Carded wool                                                                   (comparative                                                                  experiment)                                                                              0       0        10.2      30                                      Garded wool                                                                              33.5    2        0.3       3.6                                     ______________________________________                                    

EXAMPLE 3

The conditions for this Example are as in Example 1, except that 71 g ofthe stated mixture are stirred into

(a) 71 g of 10 percent strength acetic acid

(b) 3 g of glacial acetic acid

(c) 142 g of 1 N formic acid

(d) 142 g of 1 N maleic acid

(e) 142 g of 1 N hydrochloric acid

(f) 142 g of 1 N sulfuric acid

(g) 142 g of 1 N phosphoric acid

Thereafter the formulation is carried out as in Example 1. The testspecimens, of DIN A4 size, are washed for 3 hours at 40° C. in 12 l of aliquor which contains 2 g of a detergent for delicate fabrics. Table 3shows the results on the treated samples and on a untreated comparativesample.

                  TABLE 3                                                         ______________________________________                                                               Total                                                  Example                shrinkage                                              ______________________________________                                        3a                     11                                                     3b                     10                                                     3c                      9                                                     3d                     11                                                     3e                     10                                                     3f                     11                                                     3g                      9                                                     Comparative sample     49                                                     ______________________________________                                    

EXAMPLE 4

The conditions for this Example are as in Example 1, except that 36 g ofactive compound and 3.6 g of surfactant are mixed with the followingwater-miscible solvents:

(a) no solvent

(b) 3.6 g of isopropanol

(c) 36 g of isopropanol

(d) 108 g of isopropanol

(e) 36 g of methanol

(f) 36 g of acetone

(g) 36 g of methyl ethyl ketone

(h) 36 g of N-methylpyrrolidone

Using the method described in Example 1, the finishing liquors areprepared and the lengths of fabric are finished and dried. The testspecimens are washed in a washing machine, as described in Example 3.The results are shown in Table 4.

                  TABLE 4                                                         ______________________________________                                                             Total                                                    Example              shrinkage                                                ______________________________________                                        4a                   9                                                        4b                   8                                                        4c                   9                                                        4d                   8                                                        4e                   8                                                        4f                   9                                                        4g                   9                                                        4h                   9                                                        ______________________________________                                    

In the case of Example 4a it proved necessary to stir the 39.6 g ofmixture of active compound and surfactant very carefully with the acidif a clear solution was to be obtained. If instead of the 10 percentstrength acetic acid, 3 g of glacial acetic acid are used, the activecompound solution dissolves substantially more easily, and the use of asolvent is unnecessary.

EXAMPLE 5

The conditions for this Example are as in Example 1, except that theconcentration of the polyadduct of 14 moles of EO with 1 mole ofnonylphenyl is 2% (a) or 20% (b), based on active compound. The washtest is carried out as stated in Example 3. The results are shown inTable 5.

EXAMPLE 6

The conditions for this Example are as in Example 1, except that inplace of the surfactant used in Example 1 (a polyadduct of 14 moles ofEO with 1 mole of nonylphenol), 3.6 g (10%, based on active compound) ofan adduct of 8 moles of EO (a) or 20 moles of EO (b) with 1 mole ofnonylphenol are employed. The results of the washing machine test areshown in Table 5.

EXAMPLE 7

The conditions for this Example are as in Example 1, except that 3.6 gof an adduct of octylphenol with 25 moles of EO (a) or with 50 moles ofEO (b) are used. The area shrinkage on washing in the washing machine isshown in Table 5.

EXAMPLE 8

The conditions for this Example are as in Example 1, except that 3.6 gof an adduct of a C₁₂₋₁₄ -alcohol with 7 EO (a), of a C₉₋₁₁ -alcoholwith 30 EO (b) or of a C₁₂₋₁₈ -alcohol with 80 EO (c) are employed. Theresults are shown in Table 5.

EXAMPLE 9

The conditions for this Example are as in Example 1, but in addition10%, based on active compound, of an adduct of p-benzyl-o-phenylphenolwith 10 moles of EO are added to the active compound mixture. In thisway, very stable, almost water-clear finishing liquors are obtained. Theresults are shown in Table 5.

                  TABLE 5                                                         ______________________________________                                        Example              Total                                                    No.                  shrinkage                                                ______________________________________                                        5a                   8                                                        5b                   9                                                        6a                   10                                                       6b                   10                                                       7a                   9                                                        7b                   10                                                       8a                   9                                                        8b                   10                                                       8c                   10                                                       9                    8                                                        ______________________________________                                    

EXAMPLE 10

8 kg of the undyed double jersey used in Example 1 are treated for about1 hour at 20°-25° C., on a pilot-plant winch vat, in 400 l of a liquor,containing 80 g of an emulsified triisobutyl phosphate as the wettingagent and 160 g of the sodium salt of dichloroisocyanuric acid (activechlorine content 56%). The pH is brought to 4.8 with acetic acid, 160 gof sodium disulfite are then added and the material is dechlorinated for20 minutes at 30° C. After rinsing, the fabric is dried on a tenter at100° C.

The fabric is then treated with the finishing bath described in Example1, in the same way as described in Example 1 except that the amount ofactive compound and amount of acetic acid are 23.5 and 35 g,respectively. The area shrinkage of the Cubex-washed fabric is shown inTable 6.

                  TABLE 6                                                         ______________________________________                                        Amount of                                                                     active compound Relaxation    Washing                                         g/l        in %     shrinkage     shrinkage                                   ______________________________________                                        11.8       1        6.3           1.9                                         17.5       1.5      6.1           1.2                                         ______________________________________                                    

EXAMPLE 11

110 kg of 100% wool tops are treated in a top dyer for 5 minutes at 20°C. with 1.2 m³ of a liquor which contains 1.1 kg of emulsifiedtriisobutyl phosphate as the wetting agent and 1.2 l of 60% strengthacetic acid. Thereafter, 3.3 kg of the sodium salt ofdichloroisocyanurate (DCCA) are added and the pH is brought to 4.8 withacetic acid. The liquor is pumped for 10 minutes in the inward directionand for 10 minutes in the outward direction. Thereafter it is pumped for15 minutes in the outward direction whilst being heated to 35° C.Finally, dechlorination is carried out with 1.1 kg of sodium disulfite,the pH is brought to 6 with ammonia solution and the tops are dyed inthe conventional manner with wool dyes. A sample of the tops treated inthis way is dried, to provide a comparative sample for the subsequentfelting test; the main part of the tops is treated as follows in abackwasher:

1st bath: 400 l of cold water containing 200 g of an adduct ofnonylphenol with 7 moles of ethylene oxide; feed 0.2%, based on the dryweight of the tops passing through the bath.

2nd bath: cold water, pH brought to 5 with acetic acid.

3rd bath: 4 kg of the mixture of active compound, surfactant andisopropanol, described in Example 1, are mixed with 4 kg of 10% strengthacetic acid, and the mixture is diluted with water to 350 l, brought toa pH of 6 with dilute ammonia solution and made up to 400 l with water.

Feed: 10%, based on the dry weight of the wet tops passing through thebath, of an aqueous solution, prepared in accordance with the aboveformulation and containing 100 g/l of the 50% strength active compoundsolution.

4th bath: rinse with cold water.

The tops are dried at 70°-80° C.

To assess the finishing effect, the specimen of tops is stitched intocotton poplin and, using a modified version of the IWS test method TM185, is allowed to relax in 15 liters of liquor at 25° C. in the largeCubex apparatus for 55 minutes under static conditions and for 5 minuteswith agitation. It is then washed for 3 hours at room temperature (about25° C.). Thereafter, the length of the tops specimen is measured. Thereduction in length is expressed as a percentage. The results are shownin Table 7.

EXAMPLE 12

Wet woollen tops (dry weight 200 kg) which have been dyed in theconventional manner in a dyeing machine are impregnated with water in ahorizontal pad and squeezed off thoroughly, so that the remaining wetpick-up is only 55%. The tops are then impregnated, in a secondhorizontal paid with a liquor, at 20° C., which contains 120 g/l of thesodium salt of dichloroisocyanuric acid and 10 g/l of an adduct of aC₉₋₁₀ -oxo-alcohol with 5 moles of ethylene oxide, and are squeezed offto a wet pick-up of 80%. After a 3 minute dwell at 20° C., the tops aretreated with the following baths in a lisseuse:

1st bath: 400 l of cold water containing 8 kg of sodium disulfite, and800 ml of 60% strength acetic acid.

Feed: 2% of sodium disulfite (based on the dry weight of the wet topspassing through the bath).

2nd bath: cold water, pH brought to 5 with acetic acid.

3rd bath: as for the 3rd bath in Example 11

4th bath: cold water

The tops are dried at 70°-80° C.

The felting characteristics are tested as described in Example 11. Theresults are shown in Table 7.

EXAMPLE 13

5 kg of wool tops are impregnated with 35 g/l of the sodium salt ofdichloroisocyanurate and with 10 g/l of an adduct of a C₉₋₁₀-oxo-alcohol with 5 moles of ethylene oxide, and squeezed off to a wetpick-up of 100%, on a horizontal pad. Thereafter, 10 g/l of sodiumdisulfite are added for dechlorination, and the tops are rinsed withcold water, these operations being carried out in succession and on thesame padder as used for the impregnation. The chlorine-treated tops aretransferred to a pilot-plant dyeing machine, dyed in the conventionalmanner with wool dyes and rinsed. 60 l of fresh cold liquor are thenbrought to pH 9 with ammonia. A solution of 75 g of the active compoundmixture described in Example 1, 75 g of 10% strength acetic acid and 7.5g of an adduct of p-benzyl-o-phenylphenol with 10 moles of ethyleneoxide are added to this liquor, and the pH is brought to 8 with ammonia.When the liquor has been circulated for 10 minutes, dilute acetic acidis added slowly, so that after 20 minutes pH 5 is reached. The dyeingcycle is 2 minutes with the liquor circulating outwards and 5 minuteswith it circulating inwards. The liquor is drained off and the wool istaken out and dried. The results of the non-felting finishing treatmentof the samples (which were tested as described in Example 11) are shownin Table 7.

                  TABLE 7                                                         ______________________________________                                                      Amount    Amount of                                                           of DCCA   active compound                                                                           Felting                                   Example       in %      in %        shrinkage                                 ______________________________________                                        Comparative experiment                                                                      3         --          40                                        11            3         0.5*        5                                         Comparative experiment                                                                      3         --          36                                        12            3         0.5*        2                                         Comparative experiment                                                                      3.5       --          30                                        13            3.5       1.5         3                                         ______________________________________                                          *The amount of active compound absorbed corresponds to the feed.        

I claim:
 1. A process for preparing a finishing agent for reducing theshrinkage and felting of wool which comprises:dissolving (a) a compoundof the formula I ##STR2## where R¹ to R⁷ are hydrogen or low molecularweight alkyl, Q is the radical of an n-hydric alcohol or phenol, n is 2or 3 and X is a polyether chain of butoxy and/or propoxy units, with orwithout ethoxy units, which chain has an atomic ratio C:O of not lessthan 2.67:1 and a molecular weight of from 150 to 1,500 if n=2 and from150 to 3,000 if n=3, and (b) from 2 to 20 percent by weight, based onsaid compound I, of an adduct of an alcohol of 8 to 18 carbon atoms withfrom 5 to 80 moles of ethylene oxide in sufficient dilute aqueous acidto give an optically clear solution, and thereafter adding aqueousammonia solution to the solution to bring the pH of the solution to from5 to
 10. 2. The process of claim 1, wherein the compound of the formulaI, before being dissolved in aqueous acid, is dissolved in from 0.1 to10 times its amount by weight of a water-miscible solvent having aboiling point of less than 160° C.
 3. The process of claim 2, wherein analcohol of 1 to 3 carbon atoms is employed as the water-misciblesolvent.
 4. The process of claim 1 wherein the amount of said adduct isfrom 6 to 14 percent by weight, based on said compound I.
 5. The processof claim 1 wherein the pH of the solution is brought to from 7 to 9 bythe addition of an aqueous ammonia solution.